Thanks guys, I did try a search if the site before and was a little swamped, I like the 500 and the best if good for a couple of hours, so not sure but then head a tendancy to drain when off the bike so can charge it, leave it for a couple of weeks then judo on the bike and have half an hour, obviously not great. Hoping for a nice black Friday deal chime December, so a fix till Christmas would be great. Will sit down with a btw and Google later